There's another strike in Chicago and this time it's Chicago Symphony Orchestra musicians and management heading to the picket lines.

Negotiations on a new contract that expired Sept. 16 have been going on since July, and the musicians worked for one week without a contract before going on strike Saturday.

"We did everything we could on Saturday to come to an agreement," said union spokesman Steve Lester.

The two sides are at odds over health insurance.

"They've taken away what could literally be thousands of dollars from the members of the orchestra in health care costs and premium contributions," said Lester.

Musicians are being asked to increase their health care premiums from 5 percent to 12 percent. The CSO Association president said there have been no increases for the past five years, but said that's no longer an option given the rising cost of health care.

"All of us are impacted, and anybody who is lucky enough to have insurance has design changes and we all pay more toward that premium. We're asking them to do the same," said Deborah Rutter.

Musicians on average earn about $144,000 per year.

CSO musicians last went on strike in 1991, forcing the cancellation of three weeks of concerts. Both sides hope a resolution this time won't take that long.

“The Chicago Symphony Orchestra Association is committed to working diligently and negotiating in good faith with the Union to achieve a new collective bargaining agreement that provides a sustainable platform for jobs with competitive wages, benefits and work rules,” the CSO said in a statement.

The union and the CSO hope a contract can be negotiated before a big fund-raising event this weekend. Those who miss a scheduled performance due to the strike can exchange them for another show, donate their tickets or receive a refund by calling the box office at 312-294-3000.